Maeland has previously shown that gonococcal phenol-water endotoxin contains potential subgrouping determinants which he has designated the "alpha antigen." The objectives of this proposal are to extend these observations in a more refined system and are three-fold: 1) the isolation of the antigens responsible for this subgrouping from the phenol-water endotoxin extract, 2) immunologic and physicochemical analyses of these isolated antigens and 3) definition of a gonococcal subgrouping system based on these antigens and antisera produced to them. The methods employed in this proposal will include the production of large quantities of gonococcal phenol-water endotoxin from multiple organisms and isolation of the subgroup determinants by ion exchange chromatography. Immunologic studies of analyses of the individual antigens and establishment of subgroups will consist of immunodiffusion, hemagglutination, hemagglutination inhibition, complement fixation and fluorescent antibody methods. Chemical studies will include colorimetric and spectral analyses for carbohydrates and proteins. Qualitative and quantitative analyses for individual sugars and amino acids will be done by ion exchange, gas liquid and thin layer chromatography.